Altitudinal effects on habitat selection in two sympatric pipistrelle species

Altitude can profoundly influence the distribution of mammals, although the majority of studies of altitudinal impacts on distribution and abundance examine large-scale effects in mountainous environments. We investigate the potential for altitudinal effects on within habitat distribution in common and soprano pipistrelle bats (Pipistrellus pipistrellus and Pipistrellus pygmaeus) over relatively small scales on the Isle of Man, an island with a maximum altitude of 620 m above sea level. While we found no differences in habitat or altitude usage between the two species, both showed a sharp decline in activity with small increases in altitude within all habitats. This decline was steepest in deciduous and conifer woodland, and more gradual in arable land and heathland. Activity also declined more quickly with increasing altitude in the centre of habitats compared with the edge, and where water was present compared with where water was absent. We suggest that altitude may limit distribution independent of habitat, and thus is an important factor to take into account, in combination with habitat, when designing mammalian conservation strategies

Ageing and sexing the Yellowhammer Emberiza citrinella caliginosa during the non‐breeding season

Individual- or population-level analyses using ringing data require accurate identification of the age and sex of birds in the hand. Many species are difficult to age and sex: work on birds of known age and sex is essential if we are to increase the value of ringing data for these species. In this study we have used molecular sexing techniques and known-age birds to characterise plumage characteristics useful in distinguishing the age and sex of Yellowhammers Emberiza citrinella caliginosa. Tail-feather shape was useful in ageing both adult and first-year birds, supporting current ageing criteria; other features were associated with first-year birds but not with adults. Most birds, but not all, could be sexed using the amount of yellow visible on the side of head and crown. The amount of black on the longest tail-covert shaft and the amount of white on the fifth and sixth tail feathers were useful for identifying both sexes. The rump-feather shaft colour and under-tail covert coloration may be useful for sexing ambiguous birds. Our results provide additional ageing and sexing criteria for E. c. caliginosa and can be used to improve the accuracy of ringing data for this declining subspecies

Post-fledging habitat selection in a rapidly declining farmland bird, the European turtle dove Streptopelia turtur

Post-fledging survival plays a vital role in the dynamics of bird populations and yet is the least studied avian life-stage. Habitat requirements post-fledging may have important implications for behaviour and survival, especially for declining populations in landscapes that have undergone wide-scale anthropogenic modification, resulting in an altered distribution and composition of habitats. The European Turtle Dove is a widespread but rapidly declining species both within the UK and across Europe. Reduced seed food availability is thought to influence breeding success of this species, but it is not known whether post-fledging survival may also be influenced by seed availability. Here, we use leg-ring radio-tag attachments to monitor post-fledging survival and movements in 15 Turtle Dove nestlings from eight nests monitored during 2014 as part of a wider autecological study. Fledglings remained in close proximity to their nest for three weeks post-tagging, spending more than half their time in the immediate vicinity (within ∼ 20 m) of the nest. 95% of foraging trips during this period were within 329 m of the nest and fledglings selected seed-rich habitat (semi-natural grassland, low-intensity grazing, fallow and quarries). Fledglings that were heavier and in better body condition at seven days old were more likely to survive for 30 days post-fledging, and the proportion of available seed-rich habitat was a strong predictor of nestling weight and condition at seven days old. Whilst our sample size is modest, this study highlights the crucial role of food availability in juvenile survival, both while adults are feeding nestlings, and to recently fledged young, and the potential for agri-environment schemes providing foraging and nesting habitats in close proximity to provide important benefits

Editorial: Factors Affecting Host Selection by Mosquitoes: Implications for the Transmission of Vector-Borne Pathogens

Project PGC2018- 095704-B-I00 from the Spanish Ministry of Economy and Competition and from the European Regional Development Fund (FEDER

New universal ITS2 primers for high-resolution herbivory analyses using DNA metabarcoding in both tropical and temperate zones

DNA metabarcoding is a rapidly growing technique for obtaining detailed dietary information. Current metabarcoding methods for herbivory, using a single locus, can lack taxonomic resolution for some applications. We present novel primers for the second internal transcribed spacer of nuclear ribosomal DNA (ITS2) designed for dietary studies in Mauritius and the UK, which have the potential to give unrivalled taxonomic coverage and resolution from a short-amplicon barcode. In silico testing used three databases of plant ITS2 sequences from UK and Mauritian floras (native and introduced) totalling 6561 sequences from 1790 species across 174 families. Our primers were well-matched in silico to 88% of species, providing taxonomic resolution of 86.1%, 99.4% and 99.9% at the species, genus and family levels, respectively. In vitro, the primers amplified 99% of Mauritian (n = 169) and 100% of UK (n = 33) species, and co-amplified multiple plant species from degraded faecal DNA from reptiles and birds in two case studies. For the ITS2 region, we advocate taxonomic assignment based on best sequence match instead of a clustering approach. With short amplicons of 187–387 bp, these primers are suitable for metabarcoding plant DNA from faecal samples, across a broad geographic range, whilst delivering unparalleled taxonomic resolution

Active blood parasite infection is not limited to the breeding season in a declining farmland bird

Avian blood parasites can have significant impacts on adult breeding birds but studies of parasitism outside the breeding season are rare, despite their potentially important implications for host–parasite dynamics. Here we investigate temporal dynamics of blood parasite infection in adult yellowhammers Emberiza citrinella. We screened blood samples collected between December and April of 2 consecutive winters using PCR. We found a high prevalence of both Haemoproteus and Leucocytozoon parasites, with a mean prevalence of 50% across 2 winters. Prevalence of both parasites was higher during the second, colder winter of the study. Temporal trends differed between the 2 genera, suggesting that chronic Haemoproteus infections gradually disappear throughout the winter but that Leucocytozoon infections exhibit a relapse during late winter, possibly coincident with reduced food availability. Our results highlight the difference in temporal dynamics between 2 blood parasite genera infecting the same host population and emphasize the need for accurate assessment of infection status at appropriate time periods when examining impacts of, and associations with, blood parasite infection. We suggest that further research should investigate the implications of over-winter infection for birds’ physiology, behavior, and survival

High prevalence of the neonicotinoid clothianidin in liver and plasma samples collected from gamebirds during autumn sowing

Since neonicotinoid insecticides were introduced to the agricultural market, evidence of the negative impacts of these systemic compounds on non-target species has accumulated. Birds are one of the largest groups of species to inhabit farmland, but the extent of neonicotinoid exposure in avian communities is poorly understood and very little is known about how any exposure may affect wild birds. Here, free-living gamebirds were used as a model group to measure the extent of avian exposure to the neonicotinoid clothianidin via seed treatment. During a typical sowing period of winter cereals treated with clothianidin, blood and liver samples were collected simultaneously from individual hunted gamebird carcasses, both pre- (n = 18) and post-sowing (n = 57) and were analysed for clothianidin via LC/MS-MS. Body weight, fat score and faecal parasite load were also quantified in the birds to ascertain whether any of these health parameters were associated with clothianidin exposure under field conditions. Clothianidin was detected in 6% of individuals sampled pre-sowing and 89% of individuals sampled post-sowing. The frequency of clothianidin detection in plasma samples and the concentration of clothianidin in liver and plasma samples decreased significantly between the first week and 2-4 weeks post-sowing. Faecal parasite load was positively associated with concentrations of clothianidin in the liver (but not plasma) of partridge species, but there was no association between clothianidin concentration and fat score or body weight, for either sample type. This study provides clear evidence that treated seed is a source of pesticide exposure for gamebirds following autumn sowing. These findings have implications for gamebirds worldwide where seed treatments are in use, and will aid the design of any future avian biomonitoring studies for agrochemical compounds

The protozoan parasite Trichomonas gallinae causes adult and nestling mortality in a declining population of European Turtle Doves, Streptopelia turtur

Studies incorporating the ecology of clinical and sub-clinical disease in wild populations of conservation concern are rare. Here we examine sub-clinical infection by Trichomonas gallinae in a declining population of free-living European Turtle Doves and suggest caseous lesions cause mortality in adults and nestlings through subsequent starvation and/or suffocation. We found a 100% infection rate by T. gallinae in adult and nestling Turtle Doves (n = 25) and observed clinical signs in three adults and four nestlings (28%). Adults with clinical signs displayed no differences in any skeletal measures of size but had a mean 3·7% reduction in wing length, with no overlap compared to those without clinical signs. We also identified T. gallinae as the suggested cause of mortality in one Red-legged Partridge although disease presentation was different. A minimum of four strains of T. gallinae, characterized at the ITS/5·8S/ITS2 ribosomal region, were isolated from Turtle Doves. However, all birds with clinical signs (Turtle Doves and the Red-legged Partridge) carried a single strain of T. gallinae, suggesting that parasite spill over between Columbidae and Galliformes is a possibility that should be further investigated. Overall, we highlight the importance of monitoring populations for sub-clinical infection rather than just clinical disease

Friendships and Family Support Reduce Subsequent Depressive Symptoms in At-Risk Adolescents.

BACKGROUND: Early life stress (ELS) consists of child family adversities (CFA: negative experiences that happened within the family environment) and/or peer bullying. ELS plays an important role in the development of adolescent depressive symptoms and clinical disorders. Identifying factors that may reduce depressive symptoms in adolescents with ELS may have important public mental health implications. METHODS: We used structural equation modelling and examined the impact of adolescent friendships and/or family support at age 14 on depressive symptoms at age 17 in adolescents exposed to ELS before age 11. To this end, we used structural equation modelling in a community sample of 771 adolescents (322 boys and 477 girls) from a 3 year longitudinal study. Significant paths in the model were followed-up to test whether social support mediated or moderated the association between ELS and depressive symptoms at age 17. RESULTS: We found that adolescent social support in adolescence is negatively associated with subsequent depressive symptoms in boys and girls exposed to ELS. Specifically, we found evidence for two mediational pathways: In the first pathway family support mediated the link between CFA and depressive symptoms at age 17. Specifically, CFA was negatively associated with adolescent family support at age 14, which in turn was negatively associated with depressive symptoms at age 17. In the second pathway we found that adolescent friendships mediated the path between peer bullying and depressive symptoms. Specifically, relational bullying was negatively associated with adolescent friendships at age 14, which in turn were negatively associated with depressive symptoms at age 17. In contrast, we did not find a moderating effect of friendships and family support on the association between CFA and depressive symptoms. CONCLUSIONS: Friendships and/or family support in adolescence mediate the relationship between ELS and late adolescent depressive symptoms in boys and girls. Therefore, enhancing affiliate relationships and positive family environments may benefit the mental health of vulnerable youth that have experienced CFA and/or primary school bullying.AlvH was supported by a Rubicon Fellowship from the Netherlands Organization for Scientific Research. IMG was supported by a Wellcome Trust programme grant, and grants from the NIHR Collaboration for Leadership in Applied Health Research, and Care (CLAHRC) for Cambridgeshire and Peterborough; IMG, AlvH, and JLG were supported through a grant from Kidscompany UK; PBJ was supported by Wellcome Trust grants, and National Institute for Health Research grant; RAK is supported by a Wellcome grant; JLG reports grants from ESRC, grants from MRC, grants, and personal fees from Royal College of Speech, and Language therapists.This is the final version of the article. It first appeared from PLOS via http://dx.doi.org/10.1371/journal.pone.015371